This research will conduct an effectiveness study in a therapeutic community (TC) that treats, among its other residents, opiate dependent patients receiving opioid replacement therapy (methadone, LAAM, or buprenorphine). The study is an early step in development of linkages between TCs and programs providing opioid replacement therapy (ORT). The project will test primary hypotheses that both retention in the TC and opiate use will be statistically equivalent between TC clients receiving ORT compared to a similar group of TC clients not receiving ORT, and that at a 24-month follow-up the clients receiving ORT will demonstrate less utilization of health services. Research has confirmed that TC treatment significantly reduces drug use and increases prosocial behavior of drug users. Yet most TCs will not treat patients on any form of ORT. ORT is poised to expand in coming years through the use of buprenorphine, methadone in medical maintenance, and possibly through new treatment models such as office-based treatment by physicians and mobile treatment programs. The proposal builds on much preliminary work and a strong history of collaboration between the researchers and practitioners. In an evaluation of effectiveness, the study will follow two groups of residents entering a TC, comparing the equivalence of residents receiving ORT versus a group with heroin use history who are not receiving ORT and are balanced on variables that predict retention in the TC. Procedures will involve recruitment after admission to the TC and following the research participants for 24 months. The outcomes will include retention in the TC, substance use, HIV risk and criminal behaviors, and utilization of health and substance abuse services. A process evaluation will gather quantitative and qualitative information about the TC treatment experience. The project will occur at a time when drug abuse policy is changing in California, and the research will study outcomes for those participants who enter the TC under the Substance Abuse Crime Prevention Act of 2000 (Proposition 36). The products of this research will include a treatment manual that can be used by other TCs. In addition we will pilot-test the refinement of procedures to incorporate patients receiving buprenorphine, as this medication becomes more available. The research is an important part of the effort to further link the TC and opioid replacement treatment modalities.